Mechanical telephone



J. J. STILL. Mechanical Telephone.

Pater ted Mar. 2, I880.

UNITED STATES PATENT Ounce.

J. JONES STILL, OF MALVERN, PENNSYLVANIA.

MECHANICAL TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 225,177, dated March2, 1880. Application filed February 10, 1879.

T0 alt whom it may concern Be it known that I, J. JONES STILL, of Malvern, Chester county, Pennsylvania, have invented a new and useful Improvement in Acoustic or Vibratory Telephones, of which the following is a specification.

The objects of my invention are to firmly secure the diaphragm to the mouth-piece of the telephone, and to prevent the separation of the diaphragm and mouth-piece from the seat when the conducting-wire expands.

These objects I. attain in the manner which I will now proceed to describe, reference being had to the accompanying drawings, in which- Figure 1 is a sectional view of myimproved telephone with part of the wire and one hanger; Fig. 2, a sectional View, showing the different parts of the instrument detached from each other 5 and Fig. 3, a detached view of the hanger.

A represents a ring, preferably of wood, which rests against or is secured to a windowframe or other suitable support, as shown by dotted lines in Fig. 1, said support having an opening, through which passes the conductingw1re a.

B is the mouth-piece, having the usual flaring opening I); and to the inner face of this mouth-piece is secured, by pins or otherwise, a sheet-metal ring, (1, having around its outer edge a flange, which is bent around the edge of the diaphragm D, and thus securely confines the same at all points on said edge, thereby insuring the even and regular vibration of the diaphragm under the action of the sound-waves. By the use of the plate d the diaphragm may be made of any desired diameter without correspondingly enlarging the mouth-piece B, as in those telephones in which the diaphragm is secured directly to the mouthpiece.

The diaphragm is made preferably of sheet metal, such as is used for ferrotype-plates, and has a central opening for the passage of the wire a, on the end of which is formed, or to which is secured, a button, 0, a washer, f, of leather, cork, kid, or like material intervening between the button and the diaphragm, however, so as to prevent the direct contact of the two metallic surfaces.

The diaphragm rests upon a ring, 9, of elastic or semi-elastic material, fitted to a groove, 1', in the face of the ring A, the proper contact of the diaphragm with the ring at all times being insured by the tension imparted to the conducting-wire, a tension equivalent to a pull of from six to eight pounds being preferred in practice.

The inner face of the mouth-piece B is beveled, and to this beveled face the sheet-metal ring (I, carrying the diaphragm, is made to conform, so that adjacent to the inner face of the diaphragm a diverging chamber, m, is formed, this chamber being widest at the center, where it communicates with the flaring opening I) of the mouth-piece, and from this point being gradually narrowed as it approaches the edge of the diaphragm. By means of this diverging chamber the sound-waves are distributed so as to act proportionately on all parts of the diaphragm, thereby insuring a well-defined vibration and clear tone.

The washerf and ring 9 also aid in securing clearness of tone, as said washer and ring pre vent the direct contact of two metallic surfaces, or of a metallic surface and a wooden surface, which, in acoustic telephones as usually constructed, causes a jinglin g sound to be imparted to the tones of the voice, and prevents that clear and distinct enunciation which is desirable.

Hung to the mouth-piece B by means of a cord, at, is a wooden pin, F, which furnishes a simple and convenient means of sounding a call-signal on the instrument, the button 0 being struck lightly with the point of the pin F when it is desired to attract the attention of a person at the other end of the line.

The hangers for supporting the conductingwire to consist of blocks J ofhard rubber, hung to suspending wires 15, by which they may be attached to any suitable support. Each block has an opening, a, through which the wire a passes, and from this opening to the edge of the block extends a slot, 00, through which the wire may be readily slipped into its place or removed. The hard-rubber hangers interfere but little with the conducting power of the wire, so that the line may be made longer than usual without sacrificing the clearness or volume of the tone.

I claim as my inventionkept in contact with the ring 9 by means of 1. The combination of the mouth-piece B, the tension upon the conducting-wire, as set with the sheet-metal ring (1 secured thereto, forth. projecting la terally therefrom, and having a In testimony whereof I have signed my name 5 fiangededge bent round the edge of the diato this specification in the presence of two sub- 15 phragin I), all substantially as set forth. scribing Witnesses. 2. The combination of the conducting-wire J. JONES STILL. a, the ring A, the diaphragm D, and the elas- W'itnesses: tic or semi-elastic ring 9 interposed between H. MORGAN RUTH, 10 the ring A and diaphragm D, the latter being GEORGE P. STILL. 

